WATCH: Waterspout On Lake Michigan

At least two waterspouts were seen over Lake Michigan on Thursday, near the Wisconsin border, amid strong winds and a marine warning issued by the National Weather Service.

The Associated Press says the waterspouts — tornadoes that form over the water — merged into one and then split again. The video below, taken by an amateur in Pleasant Prairie, Wis., appears to be a single, merged, waterspout: